Fabric Substrate and Manufacturing Method Thereof

ABSTRACT

According to the present invention, there is provided a fabric substrate for mounting a light emitting element. The fabric substrate includes a fabric layer including at least one fabric, a stress buffer layer that is disposed on the fabric layer and minimizes an occurrence of physical strain and stress caused by bending the fabric layer, and a flattening layer that is disposed on the stress buffer layer and provides a flat surface to allow a light emitting element to operate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Korean Patent Application No.10-2018-0139958 filed Nov. 14, 2018 and Korean Patent Application No.10-2019-0135190 filed Oct. 29, 2019, the disclosures of which are herebyincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Field of Invention

The present invention relates to a fabric substrate and a manufacturingmethod thereof, and more particularly, to a fabric substrate having avery low surface roughness and an excellent interface property and amanufacturing method thereof.

Description of Related Art

As the next generation display technology, various displays such as aflexible display and a wearable display have been researched. Althoughvarious research results using flexible substrates such as a polyimide(PI) film, a polyester film, thin glass, and a glass fiber sheet havebeen reported for the flexible display, the wearable display is still inan early research stage, and many research results have not beenobtained.

As a manufacturing method of the wearable display, which has beencurrently reported, a method in which a fabric itself emits light, forexample, by adding an optical fiber or an electroluminescent (EL) wireto a fabric, or a method in which a fabric substrate is manufactured bybinding polymers to the upper portion of a fabric and flattening thefabric, and then a light emitting element is formed on the upper portionof the obtained fabric substrate are provided.

The wearable display using the fabric substrate has advantages of lowcost and a relatively simple manufacturing process. However, thewearable display using a fabric substrate in the related art isconfigured by binding polymers to the entire surface of a fabric andflattening the fabric. Accordingly, this wearable display is flexible,but has large physical strain and large stress. Thus, the wearabledisplay in the related art has a problem that it is difficult to achievea foldable or stretchable property.

For the wearable display using a fabric substrate in the related art, amethod of coating fabric with a solution or a method of bonding aplastic substrate to the fabric by thermocompression is used foroperating a light emitting element on the fabric. However, the formermethod has a problem that it is difficult to sufficiently smooth therough surface of the fabric, and thus the light emitting element doesnot operate stably, and the latter method has a problem in that theplastic substrate and the fabric are deformed by heat, and thusselection of the materials has significant limitations.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to solve the above-describedproblems and other problems. Another object thereof is to provide afabric substrate having a very low surface roughness and an excellentinterface property and a manufacturing method thereof.

Still another object thereof is to provide a fabric substrate in whichheat is not applied to the fabric, and thus it is possible to maintainflexibility of the fabric without an occurrence of strain by heat, and amanufacturing method thereof.

Yet another object thereof is to provide a fabric substrate in which itis possible to minimize an occurrence of physical strain and internalstress, and a manufacturing method thereof.

Still yet another object thereof is to provide a fabric substrate and amanufacturing method thereof in which mass production with low cost ispossible based on a solution process under conditions of predeterminedpressure and/or temperature.

Another further object thereof is to provide a fabric substrate havingexcellent breathability, elasticity, and flexibility, and amanufacturing method thereof.

To achieve the above or other objects, an exemplary embodiment of thepresent invention provides a fabric substrate including a fabric layerincluding at least one fabric, a stress buffer layer that is disposed onthe fabric layer and minimizes an occurrence of physical strain andstress caused by bending the fabric layer, and a flattening layer thatis disposed on the stress buffer layer and provides a flat surface toallow a light emitting element to operate.

Preferably, the stress buffer layer is formed of a material havingelasticity and adhesiveness. In addition, the stress buffer layer isformed of a material having a Young's modulus of 500 MPa or less. Inaddition, the stress buffer layer is formed to have a thickness of 0.1μm or more. In addition, the stress buffer layer is formed of asilicon-based material capable of being cured at room temperature.

More preferably, the flattening layer is formed of a material which hasa surface roughness of several nanometers (nm) or less and an interfaceproperty suitable for forming a thin film. In addition, the flatteninglayer is formed of a material having a Young's modulus of 0.1 GPa ormore. In addition, the flattening layer is formed to have a thickness of30 μm or less. In addition, the flattening layer contains at least oneof photocurable epoxy resin (SU-8), polyethylenenaphthalate (PEN),polyimide (PI), polyethylene terephthalate (PET), polyvinyl alcohol(PVA), acrylate, polyurethane, and polydimethylsiloxane.

More preferably, at least one of the stress buffer layer and theflattening layer is formed of a UV curable material. In addition, atleast one of the stress buffer layer and the flattening layer includesmultiple openings corresponding to a fabric-like pattern.

Another exemplary embodiment of the present invention provides amanufacturing method of a fabric substrate including disposing asacrificial layer on a support substrate and disposing a flatteninglayer on the sacrificial layer, disposing a stress buffer layer on theflattening layer, disposing a fabric layer on the stress buffer layer,and applying predetermined pressure in a direction of the fabric layer,and generating a fabric substrate in which the flattening layer, thestress buffer layer, and the fabric layer are sequentially stacked, byremoving the sacrificial layer disposed between the support substrateand the flattening layer.

More preferably, the manufacturing method of a fabric substrate furtherincludes washing a contaminant on a surface of the support substrate. Inaddition, the manufacturing method of a fabric substrate furtherincludes hardening the stress buffer layer at room temperature for apredetermined time.

More preferably, in the disposing of the sacrificial layer, thesacrificial layer is stacked by a predetermined coating process, and thesacrificial layer is cured by being heated at a predeterminedtemperature for a predetermined time. In addition, in the disposing ofthe flattening layer, the flattening layer is stacked by a predeterminedcoating process, and the flattening layer is cured by being heated at apredetermined temperature for a predetermined time or by beingirradiated with a UV ray having a predetermined wavelength for apredetermined time.

More preferably, in the generating of the fabric substrate, thesacrificial layer is removed by a predetermined solvent. Here, thesacrificial layer is formed of a material which is freely soluble in asolvent.

More preferably, the manufacturing method of a fabric substrate furtherincludes forming a metal pattern layer having a reversed pattern of afabric-like pattern, between the support substrate and the sacrificiallayer by a photolithography process. In addition, the manufacturingmethod of a fabric substrate further includes curing a portion of theflattening layer and the stress buffer layer by irradiation with UV raysin a direction of a lower surface of the support substrate, andselectively etching a portion of the flattening layer and the stressbuffer layer, in which UV curing is not caused, with a developer.

Effects of the fabric substrate and the manufacturing method thereofaccording to the exemplary embodiments of the present invention are asfollows.

According to at least one exemplary embodiment of the present invention,the surface roughness is very low, and the interface property isexcellent, and thus it is possible to form and operate various thin-filmlight emitting elements.

According to at least one exemplary embodiment of the present invention,since heat is not directly applied to the fabric in a process ofmanufacturing the fabric substrate, strain by heat does not occur, andthus the exemplary embodiment can be applied to all fabrics.

According to at least one exemplary embodiment of the present invention,since the substrate has flexibility similar to that of a fabric, it ispossible to wrinkle the substrate in various directions like actualclothing, and to operate the light emitting element even after apredetermined number of times of repetitive bending.

According to at least one exemplary embodiment of the present invention,functionality and breathability similar to those of a fabric areimparted, and thus it is possible to provide a comfortable and cool fitlike actual clothes.

The effects which can be achieved by the fabric substrate and themanufacturing method thereof according to the exemplary embodiments ofthe present invention are not limited to those mentioned above, andother effects which are not mentioned above may be clearly understood bythose skilled in the art from the following descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view illustrating a fabric substrate accordingto an exemplary embodiment of the present invention.

FIG. 1B is a cross-sectional view of the fabric substrate taken alongline I-I in FIG. 1A.

FIGS. 2A and 2B are diagrams illustrating electro-opticalcharacteristics of a light emitting element in accordance with a type ofsubstrate and whether or not a bending test is performed on the fabricsubstrate.

FIGS. 3A to 3G are diagrams illustrating a manufacturing method of thefabric substrate according to an exemplary embodiment of the presentinvention.

FIG. 4A is a perspective view illustrating a fabric substrate accordingto another exemplary embodiment of the present invention.

FIG. 4B is a cross-sectional view of the fabric substrate taken alongline I-I in FIG. 4A.

FIGS. 5A and 5B are diagrams illustrating a shape of a stress bufferlayer and a flattening layer constituting the fabric substrate in FIG.4A.

FIGS. 6A to 6G are diagrams illustrating a manufacturing method of afabric substrate according to another exemplary embodiment of thepresent invention.

FIG. 7A is a perspective view illustrating a fabric substrate accordingto yet another exemplary embodiment of the present invention.

FIG. 7B is a cross-sectional view of the fabric substrate taken alongline I-I in FIG. 7A.

FIGS. 8A and 8B are diagrams illustrating a shape of a stress bufferlayer and a flattening layer constituting the fabric substrate in FIG.7A.

FIGS. 9A to 9G are diagrams illustrating a manufacturing method of afabric substrate according to yet another exemplary embodiment of thepresent invention.

FIG. 10 is a perspective view illustrating an electroluminescence fabricaccording to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, exemplary embodiments disclosed in this specification willbe described in detail with reference to the accompanying drawings. Thesame or similar components are denoted by the same reference signs forall reference signs, and repetitive descriptions thereof will beomitted. In the following descriptions of exemplary embodimentsaccording to the present invention, in a case where a description that alayer (film), a region, a pattern, or a structure is formed “on” or“under” a substrate, a layer (film), a region, a pad, or a pattern ismade, “on” and “under” include a case of directly forming or(indirectly) forming with another layer interposed therebetween. Inaddition, the criteria for being on or under a layer will be describedbased on the drawings. In the drawings, for easy and clear descriptions,the thickness or the size of each layer are illustrated with beingexaggerated or omitted, or are schematically illustrated. In addition,the size of each component does not necessarily reflect the actual size.

In describing the exemplary embodiments disclosed here, if it isdetermined that the detailed descriptions of the related knowntechnology may obscure the gist of the exemplary embodiments herein, thedetailed description thereof will be omitted. In addition, theaccompanying drawings are only for easily understanding the exemplaryembodiments disclosed herein, the technical spirit disclosed in thespecification are not limited by the accompanying drawings, and allchanges, equivalents, and substitutes are included in the spirit andscope of the present invention.

According to the present invention, a fabric substrate having a very lowsurface roughness and an excellent interface property, and amanufacturing method thereof are provided. In addition, according to thepresent invention, a fabric substrate in which heat is not applied to afabric, and thus it is possible to maintain flexibility of the fabricwithout an occurrence of strain by heat, and a manufacturing methodthereof are provided. In addition, according to the present invention, afabric substrate in which it is possible to minimize an occurrence ofphysical strain and internal stress, and a manufacturing method thereofare provided. In addition, according to the present invention, a fabricsubstrate and a manufacturing method thereof in which mass productionwith low cost is possible based on a solution process under conditionsof predetermined pressure and/or temperature is provided. In addition,according to the present invention, a fabric substrate having excellentbreathability, elasticity, and flexibility, and a manufacturing methodthereof are provided.

The term “fabric” described in the specification refers to a fabricbeing a plane sifter which is obtained by vertically interlacing andinterweaving a warp yarn and a weft yarn, and has a predetermined area,as defined by a dictionary definition. However, “the fabric” defined inthe specification includes all kinds of fabrics such as syntheticfibers, recycled fibers, natural fibers, cotton, polyester, leather, andlinens, in addition to woven fabrics in a dictionary sense.

Various exemplary embodiments of the present invention will be describedbelow with reference to the drawings.

FIG. 1A is a perspective view illustrating a fabric substrate accordingto an exemplary embodiment of the present invention. FIG. 1B is across-sectional view of the fabric substrate taken along line I-I inFIG. 1A.

With reference to FIGS. 1A and 1B, according to an exemplary embodimentof the present invention, a fabric substrate 100 may include a fabriclayer 110, a stress buffer layer 120 on the fabric layer 110, and aflattening layer 130 on the stress buffer layer 120.

The fabric layer 110 is under the stress buffer layer 120 and theflattening layer 130 and may have a function to support the stressbuffer layer 120 and the flattening layer 130.

The fabric layer 110 is configured with at least one fabric. The fabriclayer 110 may include, for example, all kinds of fabrics such assynthetic fibers, recycled fibers, natural fibers, cotton, polyester,leather, and linens. According to the present invention, all kinds offabrics can be used as the fabric substrate 100 because heat is notapplied to the fabric in a manufacturing process, and thus strain byheat does not occur.

The stress buffer layer (or coalescent layer, 120) is disposed on thefabric layer 110. At this time, the stress buffer layer 120 may beformed by at least one method of spin coating, bar coating, dip coating,and lamination.

The stress buffer layer 120 disposed on the fabric layer 110 may beslowly hardened under conditions of predetermined pressure and/ortemperature, when a predetermined time elapsed. That is, in the stressbuffer layer 120, a liquid substance having high viscosity is slowlyhardened by moisture in the atmosphere, and is changed into a solidmaterial such as rubber, which is very flexible and elastic.

The stress buffer layer 120 may function to minimize an occurrence ofphysical strain and internal stress caused by repetitively bending thefabric layer 110. In addition, the stress buffer layer 120 may functionto cause the fabric layer 110 and the flattening layer 130 to firmlyadhere to each other. For this, the stress buffer layer 120 may beformed of a material having elasticity and adhesiveness.

The stress buffer layer 120 may be formed of a material having a Young'smodulus of 500 MPa or less in order to minimize the occurrence of stressin the fabric substrate 100 and to secure flexibility of the fabricsubstrate 100. In addition, the stress buffer layer 120 may be formed ofa material having elasticity as large as physical breakdown does notoccur even at strain of 1% or more. In addition, the stress buffer layer120 may be formed of a material which is highly flexible and elastic,such that the strain occurring in the fabric layer 110 is nottransferred to the flattening layer 130.

The stress buffer layer 120 may be formed of a material which may behardened under atmospheric pressure or room temperature, in order not todirectly apply heat to a fabric in manufacturing a fabric substrate.Representatively, a silicon (Si) based material may be used for such astress buffer layer 120. As an example, a polydimethylsiloxane (PDMS)based silicon material may be used for the stress buffer layer 120, andthe exemplary embodiment is not necessarily limited thereto.

The stress buffer layer 120 may be formed to have a thickness of 0.1 μmto 100 μm, preferably, a thickness of 1 μm to 10 μm such that it ispossible to minimize the occurrence of strain in the fabric substrate100, and to secure sufficient adhesion power.

The flattening layer 130 may be disposed on the stress buffer layer 120.At this time, the flattening layer 130 may be formed by at least onemethod of spin coating, bar coating, dip coating, and lamination.

The flattening layer 130 disposed on the stress buffer layer 120 may becured by applying heat at a predetermined temperature for apredetermined time. Meanwhile, as another example, the flattening layer130 may be cured by being irradiated with a UV ray having apredetermined wavelength for a predetermined time.

Generally, threads constituting fabric are made of several strands offiber, and thus the surface of the fabric is rough in many cases. Thus,flattening is mostly required for stacking a light emitting element onthe fabric.

The flattening layer 130 may function to improve smoothness of thefabric substrate 100. That is, the flattening layer 130 may provide aflat surface allowing a light emitting element to grow by a thin filmvapor deposition process. In addition, the flattening layer 130 mayprovide a flat surface allowing the light emitting element to normallyoperate. For this, the flattening layer 130 may be formed of a materialwhich has a surface roughness which is several nanometers (nm) or lessand is similar to those of glass, and an interface property suitable forforming a thin film.

The flattening layer 130 may be formed of a material having a Young'smodulus of 0.1 GPa or more in order to minimize the occurrence of strainin the light emitting element mounted on the surface of the flatteninglayer. As an example, the flattening layer 130 may be formed ofcarbon-based polymers such as photocurable epoxy resin (SU-8),polyethylenenaphthalate (PEN), polyimide (PI), polyethyleneterephthalate (PET), polyvinyl alcohol (PVA), acrylate, polyurethane,and polydimethylsiloxane. The material of the flattening layer is notnecessarily limited thereto.

The flattening layer 130 may be formed to have a thickness of 50 μm orless, preferably, a thickness of 30 μm or less, such that a thin film asthe flattening layer can be formed on the stress buffer layer 120.

As described above, an electroluminescence fabric may be configured in amanner that one or more light emitting elements (not illustrated) aremounted on the fabric substrate 100 formed by sequentially stacking thefabric layer 110, the stress buffer layer 120, and the flattening layer130.

FIG. 2 is a diagram illustrating electro-optical characteristics of thelight emitting element in accordance with a type of substrate andwhether or not a bending test is performed on the fabric substrate.

FIG. 2 illustrates a graph obtained by simulating electro-opticalcharacteristics of a light emitting element mounted on a glasssubstrate, a graph obtained by simulating electro-opticalcharacteristics of a light emitting element mounted on a fabricsubstrate, and a graph obtained by simulating electro-opticalcharacteristics of a light emitting element after a bending test isperformed, a predetermined number of times or more, on a fabricsubstrate on which the light emitting element is mounted, with apredetermined bending radius.

For the electro-optical characteristics of the light emitting element,which have been measured by the simulations, luminance with a change ofa voltage, current density with a change of a voltage, and currentefficiency with a change of current density are provided. Theperformance of the light emitting element can be recognized bycomparison of the electro-optical characteristics.

As illustrated in FIG. 2, the electro-optical characteristics of thelight emitting element mounted on the glass substrate are not largelydifferent from the electro-optical characteristics of the light emittingelement mounted on the fabric substrate. Thus, it is possible torecognize that it is possible to recognize that the fabric substrateaccording to the present invention can stably operate the light emittingelement and maintain the performance of the light emitting element,similar to the glass substrate. In addition, the electro-opticalcharacteristics of the light emitting element mounted on the fabricsubstrate is not largely different from the electro-opticalcharacteristics of the light emitting element after a predeterminedbending test is performed on the fabric substrate in which the lightemitting element is mounted. Thus, it is possible to recognize that itis possible to stably operate the light emitting element and to maintainthe performance of the light emitting element because of high durabilityof the fabric substrate even though the fabric substrate according tothe present invention is repetitively bent with a predetermined bendingradius a predetermined number of times or more.

FIGS. 3A to 3G are diagrams illustrating a manufacturing method of thefabric substrate according to the exemplary embodiment of the presentinvention.

With reference to FIG. 3A, a support substrate 310 having predeterminedsize and thickness may be prepared. At this time, a flat substrate suchas a glass substrate, a quartz substrates, a plastic substrates, awafer, and the like can be used as the support substrate 310.

Then, a contaminant on the surface of the support substrate 310 may beremoved with a washing solution. DI water may be used as the washingsolution, and the exemplary embodiment is not necessarily limitedthereto.

With reference to FIG. 3B, a sacrificial layer 320 may be stacked on thesupport substrate 310 with a spin coating process under conditions ofpredetermined pressure and/or temperature. Then, the sacrificial layer320 may be firmly cured by applying heat at a predetermined temperaturefor a predetermined time. At this time, the sacrificial layer 320 may beformed on the support substrate 310 to have a thickness of 0.01 μm ormore.

The sacrificial layer 320 stacked on the support substrate 310 may beformed of a material which is freely soluble in a solvent. As anexample, the sacrificial layer 320 may be formed with polyvinyl alcohol(PVA), copper (Cu), or polymethyl methacrylate (PMMA). In a case wherethe sacrificial layer 320 is formed with polyvinyl alcohol, DI water maybe used as a solvent for dissolving the sacrificial layer. In a casewhere the sacrificial layer 320 is formed with copper, a Cu etchant maybe used as the solvent for dissolving the sacrificial layer. In a casewhere the sacrificial layer 320 is formed with PMMA, isopropyl alcohol(IPA) may be used as the solvent for dissolving the sacrificial layer.In the exemplary embodiment, as an example, a case where the sacrificiallayer is formed with polyvinyl alcohol will be described below.

With reference to FIG. 3C, flattening layer 330 may be stacked on thesacrificial layer 320 with a spin coating process under conditions ofpredetermined pressure and/or temperature. Then, the flattening layer330 may be firmly cured by applying heat at a predetermined temperaturefor a predetermined time or by being irradiated with a UV ray having apredetermined wavelength for a predetermined time. At this time, theflattening layer 330 may be formed on the sacrificial layer 320 to havea thickness of 30 μm or less.

The flattening layer 330 may be formed of a material having a Young'smodulus of 0.1 GPa or more. As an example, the flattening layer 330 maybe formed of a photocurable epoxy resin (SU-8) material.

With reference to FIGS. 3D and 3E, a stress buffer layer 340 may bestacked on the flattening layer 330 with a spin coating process underconditions of predetermined pressure and/or temperature.

Then, a fabric layer (or fabric, 350) may be stacked on the stressbuffer layer 340 with a lamination process. That is, the fabric layer350 is disposed on the stress buffer layer 340, and then predeterminedpressure is applied in a direction of the fabric layer 350 for apredetermined time. This is because the stress buffer layer 340 in aliquid state is caused to be absorbed to the fabric layer 350 so as toimprove an adhesive force. In such a state, the stress buffer layer 340is hardened under a condition of atmospheric pressure or roomtemperature when a predetermined time elapsed. Thus, the stress bufferlayer 340 may cause the flattening layer 330 and the fabric layer 350 tobe firmly bound to each other (firmly adhere to each other).

The stress buffer layer 340 may be formed on the flattening layer 330 tohave a thickness of 0.1 μm or more, preferably, a thickness of 1 μm to10 μm. In addition, the stress buffer layer 340 may be formed of amaterial having a Young's modulus of 500 MPa or less. As an example, thestress buffer layer 340 may be formed of a PDMS-based silicone material.

In a case of the above stacking process, the stress buffer layer 340located under the fabric layer 350 is hardened at room temperature.Thus, all kinds of fabrics such as synthetic fibers, recycled fibers,natural fibers, cotton, polyester, leather, and linens may be used forthe fabric substrate.

With reference to FIGS. 3E and 3F, a substrate structure in which thesupport substrate 310, the sacrificial layer 320, the flattening layer330, the stress buffer layer 340, and the fabric layer 350 aresequentially stacked may be immersed in a predetermined solvent. At thistime, DI water may be used as the solvent.

If a predetermined time (for example, 24 hours) has elapsed from whenthe substrate structure is immersed, the sacrificial layer 320 disposedbetween the support substrate 310 and the flattening layer 330 isgradually dissolved by the DI water, and disappears. Thus, the supportsubstrate 310 is naturally separated from the substrate structure. Then,the substrate structure is drawn out from the DI water, and then isdried under atmospheric pressure and/or room temperature for apredetermined time. In this manner, a fabric substrate is manufactured.

As described above, the fabric substrate 100 according to the exemplaryembodiment of the present invention has advantages that the surfaceroughness is very low, the interface property is excellent, and thus itis possible to form and operate various kinds of thin-film lightemitting elements. In addition, since heat is not directly applied tothe fabric in the fabric substrate 100 in a manufacturing process,strain by heat does not occur, and thus the exemplary embodiment can beapplied to all fabrics.

Meanwhile, the stress buffer layer and the flattening layer constitutingthe fabric substrate 100 can minimize the occurrence of physical strainand mechanical stress and realize excellent bending property andwrinkling property. However, the stress buffer layer and the flatteninglayer have a problem in that the feeling of fit like actual clothes isnot provided. Thus, measures of causing the stress buffer layer and theflattening layer to have a fabric-like pattern such that the stressbuffer layer and the flattening layer may have elasticity, flexibility,and breathability similar to actual fabrics will be described below.

FIG. 4A is a perspective view illustrating a fabric substrate accordingto another exemplary embodiment of the present invention. FIG. 4B is across-sectional view of the fabric substrate taken along line I-I inFIG. 4A.

With reference to FIGS. 4A and 4B, according to another exemplaryembodiment of the present invention, a fabric substrate 400 may includea fabric layer 410, a stress buffer layer 420 on the fabric layer 410,and a flattening layer 430 on the stress buffer layer 420.

The fabric layer 410, the stress buffer layer 420, and the flatteninglayer 430 illustrated in FIG. 4A are identical or similar to the fabriclayer 110, the stress buffer layer 120, and the flattening layer 130illustrated in FIG. 1A. Thus, detailed descriptions of the fabric layer410, the stress buffer layer 420, and the flattening layer 430 will notbe repeated, and descriptions will be made focusing on a difference.

The fabric layer 410 is under the stress buffer layer 420 and theflattening layer 430 and may have a function to firmly support thestress buffer layer 420 and the flattening layer 430.

The fabric layer 410 is configured with at least one fabric. The fabriclayer 410 may include, for example, all kinds of fabrics such assynthetic fibers, recycled fibers, natural fibers, cotton, polyester,leather, and linens.

The stress buffer layer 420 may be disposed on the fabric layer 410. Atthis time, the stress buffer layer 420 may be formed by at least onemethod of spin coating, bar coating, dip coating, and lamination.

The stress buffer layer 420 may have multiple openings formed inaccordance with a predetermined pattern. As an example, as illustratedin (a) of FIG. 5, the stress buffer layer 420 may include multipleopenings corresponding to a fabric-like pattern. Although notillustrated, as another example, the stress buffer layer 420 may includemultiple openings having a circular or polygonal shape.

The stress buffer layer 420 may function to minimize an occurrence ofphysical strain and internal stress caused by repeatedly bending thefabric layer 410. In addition, the stress buffer layer 420 may functionto cause the fabric layer 410 and the flattening layer 430 to firmlyadhere to each other. For this, the stress buffer layer 420 may beformed of a material having elasticity and adhesiveness.

The stress buffer layer 420 may be formed of a material having a Young'smodulus of 500 MPa or less in order to minimize the occurrence of stressin the fabric substrate 400 and to secure flexibility of the fabricsubstrate 400. In addition, the stress buffer layer 420 may be formed ofa material which is highly flexible and elastic, such that the strainoccurring in the fabric layer 410 is not transferred to the flatteninglayer 430. The stress buffer layer 420 may be formed of an ultra-violet(UV) curable material. An epoxy-based material or an acrylic materialmay be representatively used for such a stress buffer layer 420, and theexemplary embodiment is not necessarily limited thereto.

The stress buffer layer 420 may be formed to have a thickness of 0.1 μmto 100 μm, preferably, a thickness of 1 μm to 10 μm such that it ispossible to minimize the occurrence of strain in the fabric substrate400, and to secure sufficient adhesion power.

The flattening layer 430 may be disposed on the stress buffer layer 420.At this time, the flattening layer 430 may be formed by at least onemethod of spin coating, bar coating, dip coating, and lamination.

The flattening layer 430 may be formed to have the same shape as that ofthe stress buffer layer 420. That is, the flattening layer 430 mayinclude multiple openings formed in accordance with the predeterminedpattern. As an example, as illustrated in (b) of FIG. 5, the flatteninglayer 430 may include multiple openings corresponding to a fabric-likepattern. At this time, the multiple openings may be formed at positionsin the flattening layer 430, which correspond to positions of themultiple openings formed in the stress buffer layer 420.

The flattening layer 430 may function to improve smoothness of thefabric substrate 400. That is, the flattening layer 430 may provide aflat surface allowing a light emitting element to grow by a thin filmvapor deposition process. In addition, the flattening layer 430 mayprovide a flat surface allowing the light emitting element to normallyoperate. For this, the flattening layer 430 may be formed of a materialwhich has a surface roughness which is several nanometers (nm) or lessand is similar to those of glass, and an interface property suitable forforming a thin film.

The flattening layer 430 may be formed of a material having a Young'smodulus of 0.1 GPa or more in order to minimize the occurrence of strainin the light emitting element mounted on the flattening layer. Theflattening layer 430 may be formed of a UV curable material. As anexample, the flattening layer 430 may be formed of carbon-based polymerssuch as photocurable epoxy resin (SU-8), polyethylenenaphthalate (PEN),polyimide (PI), polyethylene terephthalate (PET), polyvinyl alcohol(PVA), acrylate, polyurethane, and polydimethylsiloxane. The material ofthe flattening layer is not necessarily limited thereto.

The flattening layer 430 may be formed to have a thickness of 50 μm orless, preferably, a thickness of 30 μm or less, such that a thin film asthe flattening layer can be formed on the stress buffer layer 420.

As described above, an electroluminescence fabric may be configured in amanner that one or more light emitting elements (not illustrated) aremounted on the fabric substrate 400 formed by sequentially stacking thefabric layer 410, the stress buffer layer 420, and the flattening layer430.

FIGS. 6A to 6G are diagrams illustrating a manufacturing method of afabric substrate according to yet another exemplary embodiment of thepresent invention.

With reference to FIG. 6A, a support substrate 610 having predeterminedsize and thickness may be prepared. At this time, a flat substrate suchas a glass substrate, a quartz substrate, a plastic substrate, a wafer,and the like can be used as the support substrate 610.

Then, a contaminant on the surface of the support substrate 610 may beremoved with a washing solution. DI water may be used as the washingsolution, and the exemplary embodiment is not necessarily limitedthereto.

A thin metal film 620 may be formed on the support substrate 610 ofwhich washing is finished, to have a predetermined thickness. As amaterial of the thin metal film 620, metal allowed to be patterned, forexample, chromium (Cr), manganese (Mn), aluminum (Al), iron (Fe),titanium (Ti), nickel (Ni), molybdenum (Mo), silver (Ag), gold (Au),silicon (Si), Zinc (Zn) and alloys thereof may be used.

With reference to FIG. 6B, a photolithography process may be performedon the thin metal film 620 deposited on the support substrate 610, toform a metal pattern layer having a reversed pattern (referred to as“reversed fabric-like pattern” below for easy description) of thefabric-like pattern. That is, an exposure process may be performed onthe thin metal film 620 with a mask 625 having a fabric-like pattern,and then a developing process of removing the thin metal film 620corresponding to a photoresist (PR) may be performed with a developer.

With reference to FIG. 6C, a sacrificial layer 630 may be stacked on thesupport substrate 610 and the metal pattern layer 620 with a spincoating process under conditions of predetermined pressure and/ortemperature. Then, the sacrificial layer 630 may be firmly cured byapplying heat at a predetermined temperature for a predetermined time.At this time, the sacrificial layer 630 may be formed on the supportsubstrate 610 and the metal pattern layer 620 to have a thickness of0.01 μm or more.

The sacrificial layer 630 stacked on the support substrate 610 and themetal pattern layer 620 may be formed of a material which is freelysoluble in a solvent. As an example, the sacrificial layer 630 may beformed with polyvinyl alcohol (PVA), copper (Cu), or polymethylmethacrylate (PMMA).

When generation of such a sacrificial layer 630 is completed, aflattening layer 640 may be stacked on the sacrificial layer 630 with aspin coating process under conditions of predetermined pressure and/ortemperature. Then, a soft-baking process of applying heat at apredetermined temperature (for example, 100 degrees) or lower to theflattening layer 640 for a predetermined time may be performed.

Then, a first UV curing process of performing irradiation with a UV rayfor a predetermined time in a direction of the lower surface of thesupport substrate 610 may be performed, and thus the flattening layer640 corresponding to regions (that is, regions through which the UV raysare transmitted) other than a region hidden by the metal pattern layer620 may be cured. When the first UV curing process is completed, ahard-baking process of applying heat at a predetermined temperature (forexample, 100 degrees) or higher to the flattening layer 640 for apredetermined time may be performed.

The flattening layer 640 may be formed of a material having a Young'smodulus of 0.1 GPa or more. The flattening layer 640 may be formed of aUV curable material. As an example, the flattening layer 640 may beformed of a photocurable epoxy resin (SU-8) material.

With reference to FIGS. 6D and 6E, a stress buffer layer 650 may bestacked on the flattening layer 640 with a spin coating process underconditions of predetermined pressure and/or temperature. When stackingof the stress buffer layer 650 is completed, a fabric layer (or fabric,660) may be stacked on the stress buffer layer 650 by a laminationprocess. That is, the fabric layer 660 is disposed on the stress bufferlayer 650, and then predetermined pressure is applied in a direction ofthe fabric layer 660 for a predetermined time. This is because thestress buffer layer 650 in a liquid state is absorbed to the fabriclayer 660 so as to improve an adhesive force.

Then, a soft-baking process of applying heat at a predeterminedtemperature (for example, 100 degrees) or lower to the stress bufferlayer 650 for a predetermined time may be performed. With such asoft-baking process, the stress buffer layer 650 may cause theflattening layer 640 and the fabric layer 660 to be firmly bound to eachother (firmly adhere to each other).

Then, a second UV curing process of performing irradiation with a UV rayfor a predetermined time in the direction of the lower surface of thesupport substrate 610 may be performed, and thus the stress buffer layer650 corresponding to regions (that is, regions through which the UV raysare transmitted) other than a region hidden by the metal pattern layer620 may be cured. If the second UV curing process is completed, ahard-baking process of applying heat at a predetermined temperature (forexample, 100 degrees) or higher to the stress buffer layer 650 for apredetermined time may be performed.

The stress buffer layer 650 may be formed of a material having a Young'smodulus of 500 MPa or less. In addition, the stress buffer layer 650 maybe formed of a UV curable material. As an example, the stress bufferlayer 650 may be formed of an epoxy-based or acrylic material.

Meanwhile, in the exemplary embodiment, a case where two UV curingprocesses are performed is described as an example. However, theexemplary embodiment is not necessarily limited thereto, and it isapparent to those skilled in the art that one UV curing process may beperformed. For example, the flattening layer 640 may be stacked on thesacrificial layer 630, and then a first soft-baking process may beperformed. Then, the stress buffer layer 650 and the fabric layer 660may be sequentially stacked on the flattening layer 640, and then asecond soft-baking process may be performed. In addition, the UV curingprocess of performing irradiation with a UV ray for a predetermined timein the direction of the lower surface of the support substrate 610 for apredetermined time may be performed, and then the hard-baking process ofapplying heat of a predetermined temperature (for example, 100 degrees)or higher to the flattening layer 640 and the stress buffer layer 650for a predetermined time may be performed.

With reference to FIG. 6F, a first substrate structure in which thesupport substrate 610, the metal pattern layer 620, the sacrificiallayer 630, the flattening layer 640, the stress buffer layer 650, andthe fabric layer 660 are sequentially stacked may be immersed in apredetermined solvent for a predetermined time. At this time, DI watermay be used as the solvent.

If a predetermined time (for example, 24 hours) has elapsed from whenthe first substrate structure is immersed, the sacrificial layer 630disposed between the support substrate 610, and the metal pattern layer620 and the flattening layer 640 is gradually dissolved by the DI water,and disappears. Thus, the support substrate 610 and the metal patternlayer 620 are naturally separated from the first substrate structure.Then, a second substrate structure constituted by the flattening layer640, the stress buffer layer 650, and the fabric layer 660 may be drawnout from DI water, and then the second substrate structure may be dried.

With reference to FIG. 6G, the second substrate structure in which theflattening layer 640, the stress buffer layer 650, and the fabric layer660 are sequentially stacked may be immersed in a predetermineddeveloper for a predetermined time. At this time, a composition in whichan ionic or nonionic surfactant is added to an inorganic and organicalkaline aqueous solution may be used as the developer, but theexemplary embodiment is not necessarily limited thereto.

If a predetermined time has elapsed from when the second substratestructure is immersed, the developer chemically reacts with portions ofthe flattening layer 640 and the stress buffer layer 650, in which UVcuring does not occur, and thus the above portions are selectivelyetched. Thus, multiple openings in accordance with the fabric-likepattern are formed in the flattening layer 640 and the stress bufferlayer 650. Then, the second substrate structure is drawn out from thedeveloper, and then is dried under predetermined conditions for apredetermined time. In this manner, a fabric substrate is manufactured.

As described above, according to another exemplary embodiment of thepresent invention, since the fabric substrate 400 has flexibilitysimilar to that of a fabric, it is possible to wrinkle the substrate invarious directions like actual clothing, and to operate the lightemitting element even after a predetermined number of times ofrepetitive bending. In addition, the fabric substrate 400 has anadvantage that functionality and breathability similar to those ofactual fabrics are imparted, and thus it is possible to provide acomfortable and cool fit similar to actual clothes. FIG. 7A is aperspective view illustrating a fabric substrate according to yetanother exemplary embodiment of the present invention. FIG. 7B is across-sectional view of the fabric substrate taken along line I-I inFIG. 7A.

With reference to FIGS. 7A and 7B, according to still another exemplaryembodiment of the present invention, a fabric substrate 700 may includea fabric layer 710, a stress buffer layer 720 on the fabric layer 710,and a flattening layer 730 on the stress buffer layer 720.

The fabric layer 710, the stress buffer layer 720, and the flatteninglayer 730 illustrated in FIG. 7A are identical or similar to the fabriclayer 110 or 410, the stress buffer layer 120 or 420, and the flatteninglayer 130 or 430 illustrated in FIG. 1A or 4A. Thus, detaileddescriptions of the fabric layer 710, the stress buffer layer 720, andthe flattening layer 730 will not be repeated, and descriptions will bemade focusing on a difference.

The fabric layer 710 is under the stress buffer layer 720 and theflattening layer 730 and may have a function to firmly support thestress buffer layer 720 and the flattening layer 730.

The stress buffer layer 720 may be disposed on the fabric layer 710. Atthis time, the stress buffer layer 720 may be formed by at least onemethod of spin coating, bar coating, dip coating, and lamination.

The stress buffer layer 720 does not include multiple openings formed inaccordance with a predetermined pattern, differing from the stressbuffer layer 420 illustrated in FIG. 4A. As an example, as illustratedin (a) of FIG. 8, the stress buffer layer 720 may be formed to have athin film shape.

The stress buffer layer 720 may function to minimize an occurrence ofphysical strain and stress caused by repeatedly bending the fabric layer710. In addition, the stress buffer layer 720 may function to cause thefabric layer 710 and the flattening layer 730 to firmly adhere to eachother. For this, the stress buffer layer 720 may be formed of a materialhaving elasticity and adhesiveness.

The stress buffer layer 720 may be formed of a material which may behardened under atmospheric pressure or room temperature, in order not todirectly apply heat to a fabric in a manufacturing process of a fabricsubstrate. Representatively, a silicon (Si) based material may be usedfor such a stress buffer layer 720. As an example, apolydimethylsiloxane (PDMS) based silicon material may be used for thestress buffer layer 720, and the exemplary embodiment is not necessarilylimited thereto.

The flattening layer 730 may be disposed on the stress buffer layer 720.At this time, the flattening layer 730 may be formed by at least onemethod of spin coating, bar coating, dip coating, and lamination.

The flattening layer 730 may include multiple openings formed inaccordance with the predetermined pattern. As an example, as illustratedin (b) of FIG. 8, the flattening layer 730 may include multiple openingscorresponding to a fabric-like pattern. Although not illustrated, asanother example, the flattening layer 730 may include multiple openingshaving a circular or polygonal shape.

The flattening layer 730 may function to improve smoothness of thefabric substrate 700. For this, the flattening layer 730 may be formedof a material which has a surface roughness which is several nanometers(nm) or less and is similar to those of glass, and an interface propertysuitable for forming a thin film.

The flattening layer 730 may be formed of a material having a Young'smodulus of 0.1 GPa or more in order to minimize the occurrence of strainin the light emitting element mounted on the flattening layer. Theflattening layer 730 may be formed of a UV curable material. As anexample, the flattening layer 430 may be formed of carbon-based polymerssuch as photocurable epoxy resin (SU-8), polyethylenenaphthalate (PEN),polyimide (PI), polyethylene terephthalate (PET), polyvinyl alcohol(PVA), acrylate, polyurethane, and polydimethylsiloxane. The material ofthe flattening layer is not necessarily limited thereto.

As described above, an electroluminescence fabric may be configured in amanner that one or more light emitting elements (not illustrated) aremounted on the fabric substrate 700 formed by sequentially stacking thefabric layer 710, the stress buffer layer 720, and the flattening layer730.

FIGS. 9A to 9G are diagrams illustrating a manufacturing method of afabric substrate according to yet another exemplary embodiment of thepresent invention.

The manufacturing method of a fabric substrate illustrated in FIGS. 9Ato 9G is similar to the manufacturing method of a fabric substrateillustrated in FIGS. 6A to 6G, and thus descriptions will be madefocusing on differences.

With reference to FIG. 9A, a support substrate 910 having predeterminedsize and thickness may be prepared. Then, a contaminant on the surfaceof the support substrate 910 may be removed with a washing solution.

A thin metal film 920 may be formed on the support substrate 910 ofwhich washing is finished, to have a predetermined thickness. As amaterial of the thin metal film 920, metal allowed to be patterned, forexample, chromium (Cr), aluminum (Al), iron (Fe), titanium (Ti), nickel(Ni), molybdenum (Mo), manganese (Mn), silver (Ag), gold (Au), silicon(Si), Zinc (Zn) and alloys thereof may be used.

With reference to FIG. 9B, a photolithography process may be performedon the thin metal film 620 deposited on the support substrate 610, toform a metal pattern layer having a reversed pattern of the fabric-likepattern, that is, a reversed fabric-like pattern. That is, an exposureprocess may be performed on the thin metal film 920 with a mask 925having a fabric-like pattern, and then a developing process of removingthe thin metal film 920 corresponding to a photoresist (PR) may beperformed with a developer.

With reference to FIG. 9C, a sacrificial layer 930 may be stacked on thesupport substrate 910 and the metal pattern layer 920 with a spincoating process under conditions of predetermined pressure and/ortemperature. Then, the sacrificial layer 930 may be firmly cured byapplying heat at a predetermined temperature for a predetermined time.

If generation of such a sacrificial layer 930 is completed, a flatteninglayer 940 may be stacked on the sacrificial layer 930 with a spincoating process under conditions of predetermined pressure and/ortemperature. Then, a soft-baking process of applying heat of apredetermined temperature (for example, 100 degrees) or lower to theflattening layer 940 for a predetermined time may be performed.

Then, a UV curing process of performing irradiation with a UV ray for apredetermined time in a direction of the lower surface of the supportsubstrate 910 may be performed, and thus the flattening layer 940corresponding to regions (that is, regions through which the UV rays aretransmitted) other than a region hidden by the metal pattern layer 920may be cured. If the UV curing process is completed, a hard-bakingprocess of applying heat of a predetermined temperature (for example,100 degrees) or higher to the flattening layer 940 for a predeterminedtime may be performed.

With reference to FIGS. 9D and 9E, a stress buffer layer 950 may bestacked on the flattening layer 940 with a spin coating process underconditions of predetermined pressure and/or temperature.

Then, a fabric layer (or fabric, 960) may be stacked on the stressbuffer layer 950 with a lamination process. That is, the fabric layer960 is disposed on the stress buffer layer 950, and then predeterminedpressure is applied in a direction of the fabric layer 960 for apredetermined time. This is because the stress buffer layer 950 in aliquid state is caused to be absorbed to the fabric layer 960 so as toimprove an adhesive force. In such a state, the stress buffer layer 950is slowly hardened under atmospheric pressure or room temperature when apredetermined time elapsed. Thus, the stress buffer layer 950 may causethe flattening layer 940 and the fabric layer 960 to be firmly bound toeach other (firmly adhere to each other).

In a case of the above stacking process, the stress buffer layer 950located under the fabric layer 960 is hardened at room temperature.Thus, all kinds of fabrics such as synthetic fibers, recycled fibers,natural fibers, cotton, polyester, leather, and linens may be used forthe fabric substrate.

With reference to FIG. 9F, a first substrate structure in which thesupport substrate 910, the metal pattern layer 920, the sacrificiallayer 930, the flattening layer 940, the stress buffer layer 950, andthe fabric layer 960 are sequentially stacked may be immersed in apredetermined solvent (for example, DI water) for a predetermined time.

If a predetermined time (for example, 24 hours) has elapsed from whenthe first substrate structure is immersed, the sacrificial layer 930disposed between the support substrate 910, and the metal pattern layer920 and the flattening layer 940 is gradually dissolved by the DI water,and disappears. Thus, the support substrate 910 and the metal patternlayer 920 are naturally separated from the first substrate structure.Then, a second substrate structure constituted by the flattening layer940, the stress buffer layer 950, and the fabric layer 960 may be drawnout from DI water, and then the second substrate structure may be dried.

With reference to FIG. 9G, the second substrate structure in which theflattening layer 940, the stress buffer layer 950, and the fabric layer960 are sequentially stacked may be immersed in a predetermineddeveloper for a predetermined time.

If a predetermined time has elapsed from when the second substratestructure is immersed, the developer chemically reacts with portions ofthe flattening layer 940 and the stress buffer layer 950, in which UVcuring does not occur, and thus the above portions are selectivelyetched. Thus, multiple openings in accordance with the fabric-likepattern are formed in the flattening layer 940 and the stress bufferlayer 950. Then, the second substrate structure is drawn out from thedeveloper, and then is dried under predetermined conditions for apredetermined time. In this manner, a fabric substrate is manufactured.

As described above, according to still yet another exemplary embodimentof the present invention, since the fabric substrate 700 has flexibilitysimilar to that of a fabric, it is possible to wrinkle the substrate invarious directions like actual clothing, and to operate the lightemitting element even after a predetermined number of times ofrepetitive bending.

FIG. 10 is a perspective view illustrating an electroluminescence fabricaccording to an exemplary embodiment of the present invention.

With reference to FIG. 10, according to an exemplary embodiment of thepresent invention, an electroluminescence fabric 1000 includes a fabricsubstrate 1010, a light emitting element 1020 on the fabric substrate1010, and a sealing layer 1030 on the light emitting element 1020.

The fabric substrate 1010 may be disposed under the light emittingelement 1020 to support the light emitting element 1020. In addition, asthe fabric substrate 1010, a substrate having a very low surfaceroughness and an excellent interface property may be provided to form(that is, grow) and operate the light emitting element 1020.

The fabric substrate 1010 may include a fabric layer 1011, a stressbuffer layer 1013 on the fabric layer 1011, and a flattening layer 1015on the stress buffer layer 1013. Here, the fabric layer 1011 may bedisposed under the stress buffer layer 1013 and may have a function tosupport the stress buffer layer 1013 and the flattening layer 1015. Thestress buffer layer 1013 is disposed between the fabric layer 1011 andthe flattening layer 1015. Thus, the stress buffer layer 1013 is causedto bind (adhere to) the fabric layer 1011 and the flattening layer 1015to each other, and thus it is possible to minimize the occurrence ofstrain and stress caused by repetitively bending the fabric layer 1011.The flattening layer 1015 may be disposed on the stress buffer layer1013 to improve smoothness of the fabric substrate 1010.

The light emitting element 1020 may be formed on the fabric substrate1010 to emit light having a predetermined wavelength. Various kinds ofthin-film light emitting elements such as a light emitting diode (LED)element, an organic light emitting diode (OLED) element, a polymer lightemitting diode (PLED) element, and an inorganic EL element may be usedas the light emitting element 1020, and the exemplary embodiment is notnecessarily limited thereto. Among the above elements, the organic lightemitting diode (OLED) element is the next-generation display device thatperforms electroluminescence with electrodes having a thickness ofseveral tens to hundreds nanometers, and an organic substance. The OLEDelement attracts much attentions because the OLED element has a lowoperating voltage and high luminous efficiency, and is easy to realizetransparent and flexible characteristics. Accordingly, in this exemplaryembodiment, a case where an organic light emitting diode (OLED) elementis used as the light emitting element 1020 of the electroluminescencefabric 1000 will be described below as an example.

The organic light emitting element 1020 may be, for example, atop-emitting organic light emitting element having a top-emittingstructure, and may emit light in a direction of the sealing layer 1030located at the upper portion of the electroluminescence fabric 1000. Inthis case, if an upper electrode of the organic light emitting element1020 is formed to be thin (for example, 10 nm to 50 nm), it is possibleto emit light in the direction of the sealing layer 1030 correspondingto the upper electrode.

Meanwhile, as another example, the organic light emitting element 1020may be a bottom-emitting organic light emitting element having abottom-emitting structure, and may emit light in a direction of thefabric substrate 1010 located at the lower portion of theelectroluminescence fabric 1000. In this case, if a lower electrode ofthe organic light emitting element 1020 is formed to be thin (forexample, 10 nm to 50 nm), it is possible to emit light in the directionof the fabric substrate 1010 corresponding to the lower electrode.

The organic light emitting element 1020 may include a non-invertingstructure. In the non-inverting structure, a positive electrode layer asthe lower electrode, a hole injection layer (HIL), a hole transfer layer(HTL), an emission material layer (EML), an electron transfer layer(ETL), an electron injection layer (EIL), a negative electrode layer asthe upper electrode, and a capping layer are formed on the fabricsubstrate 1010 in this order.

As yet another example, the organic light emitting element 1020 mayinclude an inverting structure in which the negative electrode layer asthe lower electrode, the electron injection layer (EIL), the electrontransfer layer (ETL), the emission material layer (EML), the holetransfer layer (HTL), the hole injection layer (HIL), the positiveelectrode layer as the upper electrode, and the capping layer are formedon the fabric substrate 1010 in this order. Here, the hole injectionlayer, the hole transfer layer, the emission material layer, theelectron transfer layer, and the electron injection layer may constitutean organic layer of the organic light emitting element 1020. The cappinglayer is an organic layer that causes refractive indices (n) of anorganic layer and an inorganic layer which are respectively formed onand under the upper electrode to match with each other so as to improvelight extraction and protects the organic light emitting element 1020.The capping layer may be deposited on the negative electrode layer orthe positive electrode layer.

The positive electrode layer (Anode) or the negative electrode layer(Cathode) may be formed by a thermal evaporation method with silver(Ag), gold (Au), or aluminum (Al) being a conductive metal material. Thethickness of the positive electrode layer or the negative electrodelayer may be 10 nm to 200 nm. The positive electrode layer or thenegative electrode layer may include a silver nanowire, a single walledcarbon nanotube (SWCNT), a multi-wall carbon nanotube (MWCNT), andconductive polymers such as graphene or polyaniline.

In order to realize such an organic light emitting element 1020 on thefabric substrate 1010, the surface roughness is required to be, forexample, several to tens of nanometers. In addition, since the organiclight emitting element 1020 is different from an inorganic lightemitting element in that the element is easily contaminated by moisture(H₂O) or oxygen (O₂), sealing for preventing vapor permeance isrequired.

The sealing layer 1030 may be disposed on the organic light emittingelement 1020 to seal the organic light emitting element 1020. Thesealing layer 1030 may be an aluminum oxide (Al₂O₃) layer, a magnesiumoxide (MgO) layer, a multilayer thin film structure in which an aluminumoxide layer and an organic layer are alternately stacked, or amultilayer thin film structure in which an aluminum oxide layer and amagnesium oxide layer are alternately stacked. In the multilayer thinfilm structure in which the aluminum oxide layer and the organic layerare alternately stacked, the aluminum oxide layer and the organic layermay be stacked on the organic light emitting element 1020 in this order.

The sealing layer 1030 may be a multilayer thin film structure in whicha multilayer thin film sealing layer and an organic layer arealternately stacked. Here, the multilayer thin film sealing layer may beformed in a manner that at least two or more of an aluminum oxide(Al₂O₃) layer, a magnesium oxide (MgO) layer, a zinc oxide (ZnO) layer,a silicon dioxide (SiO₂) layer, and a titanium dioxide (TiO₂) layer arealternately stacked.

The organic layer may contain, for example, polyvinyl alcohol, acrylate,or UV curable polymers including Bisphenol-F. The organic layer may beformed by various methods such as thermal evaporation, spin coating, barcoating, and dip coating.

The aluminum oxide layer and the magnesium oxide layer may be formed byan atomic layer deposition method with an atomic layer deposition (ALD)device or by a chemical vapor deposition method with a chemical vapordeposition (CVD) device. The zinc oxide (ZnO) layer and the titaniumdioxide (TiO₂) layer may be formed by an atomic layer deposition methodwith an ALD device. The silicon dioxide (SiO₂) layer may be formed by anE-beam deposition device.

As described above, according to the present invention, theelectroluminescence fabric includes a fabric substrate havingflexibility like fabric and an excellent interface property, and thushas an excellent feeling of fit and does not cause heterogeneity to auser. In addition, the electroluminescence fabric is endlessly availablein connection with various smart devices.

Hitherto, the specific exemplary embodiments of the present inventionare described, but various modifications can be made in a range withoutdeparting from the gist of the present invention. The scope of thepresent invention is not limited to the above-described exemplaryembodiment, and should be defined by the claims as follows and theequivalents of the claims.

What is claimed is:
 1. A fabric substrate comprising: a fabric layerincluding at least one fabric; a stress buffer layer that is disposed onthe fabric layer and minimizes an occurrence of physical strain andstress caused by bending the fabric layer; and a flattening layer thatis disposed on the stress buffer layer and provides a flat surface toallow a light emitting element to operate.
 2. The fabric substrate ofclaim 1, wherein the stress buffer layer is formed of a material havingelasticity and adhesiveness.
 3. The fabric substrate of claim 1, whereinthe stress buffer layer is formed of a material having a Young's modulusof 500 MPa or less in order to obtain flexibility of the fabricsubstrate.
 4. The fabric substrate of claim 1, wherein the stress bufferlayer is formed to have a thickness of 0.1 μm or more.
 5. The fabricsubstrate of claim 1, wherein the stress buffer layer is formed of asilicon-based material capable of being cured at room temperature. 6.The fabric substrate of claim 1, wherein the flattening layer is formedof a material which has a surface roughness of several nanometers (nm)or less and an interface property suitable for forming a thin film. 7.The fabric substrate of claim 1, wherein the flattening layer is formedof a material having a Young's modulus of 0.1 GPa or more.
 8. The fabricsubstrate of claim 1, wherein the flattening layer is formed to have athickness of 30 μm or less.
 9. The fabric substrate of claim 1, whereinthe flattening layer contains at least one of photocurable epoxy resin(SU-8), polyethylenenaphthalate (PEN), polyimide (PI), polyethyleneterephthalate (PET), polyvinyl alcohol (PVA), acrylate, polyurethane,and polydimethylsiloxane.
 10. The fabric substrate of claim 1, whereinat least one of the stress buffer layer and the flattening layer isformed of a UV curable material.
 11. The fabric substrate of claim 1,wherein at least one of the stress buffer layer and the flattening layerincludes multiple openings corresponding to a fabric-like pattern.
 12. Amanufacturing method of a fabric substrate, comprising: disposing asacrificial layer on a support substrate and disposing a flatteninglayer on the sacrificial layer; disposing a stress buffer layer on theflattening layer, disposing a fabric layer on the stress buffer layer,and applying predetermined pressure in a direction of the fabric layer;and generating a fabric substrate in which the flattening layer, thestress buffer layer, and the fabric layer are sequentially stacked, byremoving the sacrificial layer disposed between the support substrateand the flattening layer.
 13. The manufacturing method of claim 12,further comprising: washing a contaminant on a surface of the supportsubstrate.
 14. The manufacturing method of claim 12, wherein thesacrificial layer is formed of a material which is freely soluble in asolvent.
 15. The manufacturing method of claim 12, wherein, in thedisposing of the sacrificial layer, the sacrificial layer is stacked bya predetermined coating process, and the sacrificial layer is cured bybeing heated at a predetermined temperature for a predetermined time.16. The manufacturing method of claim 12, wherein, in the disposing ofthe flattening layer, the flattening layer is stacked by a predeterminedcoating process, and the flattening layer is cured by being heated at apredetermined temperature for a predetermined time or by beingirradiated with a UV ray having a predetermined wavelength for apredetermined time.
 17. The manufacturing method of claim 12, furthercomprising: hardening the stress buffer layer at room temperature for apredetermined time.
 18. The manufacturing method of claim 12, wherein,in the generating of the fabric substrate, the sacrificial layer isremoved by a predetermined solvent.
 19. The manufacturing method ofclaim 12, further comprising: forming a metal pattern layer having areversed pattern of a fabric-like pattern, between the support substrateand the sacrificial layer by a photolithography process.
 20. Themanufacturing method of claim 19, further comprising: curing a portionof the flattening layer and the stress buffer layer by irradiation withUV rays in a direction of a lower surface of the support substrate; andselectively etching a portion of the flattening layer and the stressbuffer layer, in which UV curing is not caused, with a developer.